1. Field of the Invention
The present invention relates to a lancet cartridge that is used during collection of body fluids for use in a handy measuring instrument or the like.
2. Description of the Related Art
Compact measuring instruments are used for measuring the amount of components, for instance, glucose or cholesterol, in body fluids. A small amount of body fluid is necessary for measurement using these handy measuring instruments. For instance, in order to collect a small amount of a body fluid, a pricking instrument is used wherein a disposable lancet is fitted to a main body having a lancet-ejecting mechanism, after which an end cap is fitted to the leading end of the main body. A pricking opening is provided in the leading end of the end cap. The leading end of the end cap is pressed against the skin of the test subject, and the main body is operated; thereby, the leading end section of the lancet is caused to protrude through the pricking opening, and to prick the skin of the test subject, to collect the body fluid as a result. The following conventional approaches are adopted in order to secure a body fluid amount that is sufficient for measurement, upon collection of a body fluid using such a pricking instrument.
For instance, Japanese Patent Application Publication No. 2005-046612 discloses the feature of preparing multiple end caps having dissimilar sizes, in order to modify the depth of the leading end section of the lancet that penetrates the skin. Japanese Patent Application Publication No. 2004-237089 discloses the feature of preparing a plurality of end caps having leading end shapes that conform to the shape of collection sites, to enable appropriate collection of a body fluid at a plurality of dissimilar collection sites, for instance the fingertip, the forearm and the like.
If blood sampling is performed using a pricking instrument that is shared among a plurality of test subjects, problems of hygiene arise in that body fluids become adhered to the leading end of the end cap, and in that the leading end section of the pricking member, with the body fluid adhered thereto, becomes exposed. In order to solve the above problems, for instance, WO 2009/041110 discloses a lancet cartridge in which a lancet is integrally housed in a lancet holder. The lancet holder, having a pricking opening formed at the leading end, has the same function as the aforementioned end cap, but is disposed of together with the lancet, even if a body fluid is adhered to the leading end. Also, the lancet is housed in the lancet holder, except during pricking. Therefore, the leading end section of the lancet having a body fluid adhered thereto does not come into contact with an operator or the like. Therefore, the lancet cartridge is appropriate for preventing contamination and the like.
In such lancet cartridges, the lancet is ordinarily housed in the lancet holder, and hence it is difficult to visually check whether the lancet cartridge is a used one or not. In order to solve this problem, the lancet cartridge disclosed in WO 2009/041110 is configured in such a manner that when fitted to the pricking instrument, a small projection provided in the lancet becomes exposed through a slit that is provided in the lancet holder. It becomes possible thereby to check visually, from outside, whether the lancet cartridge is a used one or not.
However, the abovementioned conventional technology leaves room for improvement as regards the features below.
In a conventional lancet cartridge, first of all, the small protrusion exposed on the side face of the lancet holder is of reduced size, and hence it is not found that it is possible to visually check, from outside and in an easy manner, whether the lancet cartridge is a used one or not. In the conventional lancet cartridge, secondly, the lancet and the lancet holder are formed integrally with each other. Therefore, it is not possible to replace a lancet holder by another lancet holder of dissimilar shape, in order to secure a body fluid amount that is sufficient for measurement, as in the pricking instruments disclosed in Japanese Patent Application Publication No. 2005-046612 and Japanese Patent Application Publication No. 2004-237089.